The free standalone batch DWG conversion tool DWG TrueConvert is now available for download. DWG True Convert requires no AutoCAD to be present on the system.

http://www.autodesk.com/dwgtrueconvert

Past blog post about this tool and what it does:
DWG TrueView & DWG TrueConvert

Press release of DWG TrueView and DWG TrueConvert
New, Free Autodesk Tools for Viewing and Converting DWG Data Enhance Communication and Collaboration